What is the max you can grind a crank
.030 over OK or too far?
Thank you.. Lorenzo
I re-metaled a block for a 26 several weeks ago, that was ground .060 on the mains and .040 on the pins, it was an early shaft and has been in the car for several years,(hilly country as well) crack tested all OK so the owner wanted to keep using it.
Can I find .030 mains? langs does not show them in their book
30 is the max we go on rods and mains but Like Frank mentioned there have been others' who've ground more off.
We have put in 3 cranks over the years at .050 under. they will last if the crank is ground the way it should be, and the pan is straight.
.050 is as low as we could go as the pouring jig won't lend it's self to any thing smaller. Not enough babbitt for .060.
Thank you all for the input ..Lorenzo
Lorenzo, you are right, the vendors do not list .030 mains, what they have is a few sizes listed in caps for no more than a patch up job to try to take up some crank play. To do it right the block and caps are re-poured and then machined (line bored) to the right oil clearances of the crankshaft.
Places like Kohnke Rebabbitting and J&M Machining are tooled up to do this at your end of the world.
I rebuilt an engine recently which had journals .070" under. (!)
I put a different crank in it.